Frozen and refrigerated goods are normally stored in refrigerated storage rooms or “cold storage” prior to being delivered to a retailer or end user. Frequent access to these cold stores is made via doors into the stores to both deliver and remove products therefrom. Access may be for personnel only but, more often, is for loading vehicles, such as fork lift trucks, that are able to deliver and remove products in bulk from the cold store.
The use of heavily insulated solid panel cold store doors with heated perimeter seals is one solution to maintain the integrity of a cold room envelope. However, a problem with this type of door is that damage to the door caused by collisions between fork lift truck traffic and the door is virtually unavoidable, even with high speed bi-parting doors. Cold store operators have recognized this problem and have tried to overcome it by adopting alternative door types, such as fabric roll-up doors. This has met with limited success since the doors inevitably open more slowly than equivalent-sized bi-parting horizontal sliding doors. If the door is left open, an inflow of relatively warm air is able to enter the cold store and cold air flows out of the store. This is undesirable because it allows ice crystals to form in the store and moisture droplets to form in the relatively warm side and also contributes significantly to the load on the refrigeration plant. Furthermore, ice can form on the floor around the doorway which is a safety concern. What is needed is an improved conditioned vestibule for a cold storage doorway.